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Thread ID: 142349 2016-06-15 22:16:00 car battery question 1101 (13337) PC World Chat
Post ID Timestamp Content User
1421986 2016-06-15 22:16:00 How long should a car be able to leave the parking lights on without the batt going flat ?

I accidently left my parking lights on for what seemed like 4 hours, (may have been longer ?), after that the batt was flat .

Is my car batt at its end of usefull life? .No issues with cold cranking etc & it charged up within 10 minutes of driving .
Im guessing the batt is 3-5 years old , Id have to dig out the receipt to be sure
1101 (13337)
1421987 2016-06-15 22:23:00 How long should a car be able to leave the parking lights on without the batt going flat ?

I accidently left my parking lights on for what seemed like 4 hours, (may have been longer ?), after that the batt was flat .

Is my car batt at its end of usefull life? .No issues with cold cranking etc & it charged up within 10 minutes of driving .
Im guessing the batt is 3-5 years old , Id have to dig out the receipt to be sure

That's probably about their life. Maybe longer if the car regularly does a good drive (like hours)
psycik (12851)
1421988 2016-06-15 23:04:00 I don't know, after looking after the servicing of our 3 school vans for 9 years, I have never had to replace a battery in them. I don't know how long the batteries had been in them before I took over the maintenance. They do 20,000K+ per year. Always start first kick which probably helps.

Myself, had to replace 2 batteries in various cars over about 20 cars in 58 years.

Ken
kenj (9738)
1421989 2016-06-15 23:15:00 My daughter has her car parked at my home with a dying battery. So I tested it with a multi meter for static voltage and both crank - load voltage (leave running to also check alternator charge output - should be about 14 V), and parasitic draw (current drain). Crank voltage was low at 8.5 V should be at least 9.6V. current drain is around 27mA - relatively low and therefore OK. The clock was the cause of drain.

- Vids on how to do battery tests and load (www.youtube.com), parasitic draw (www.youtube.com) and alternator charge tests. (www.youtube.com)

Her car battery been in use since December 2012 according to the label's date code. 4.5 yeas old. so concluded the car needs a new battery....
kahawai chaser (3545)
1421990 2016-06-15 23:30:00 I may just replace the batt anyway, nothing worse than being stranded somewhere with a dead batt .
I'll check the crank voltage with old & new batt , just out of interest

has anyone got one of those small emergency car starters (jumpstarters), small lipo pack designed to start the car when batt is dead?
that would be a great bit of kit, if the price was right. $200 is a bit much for my pockets , anyone know of where I can get them cheaper?
like this , but cheaper
www.supercheapauto.co.nz

cheers
1101 (13337)
1421991 2016-06-15 23:43:00 in petrol cars the batteries don't seam to last long.
in diesels however they last a lot longer, tho not sure with common rail diesels as the injection system draws a lot of power.

by just driving it you will not charge it up fully (unless you do really long trips). really need to put a battery charger on it.

jump starters are ok but only if the battery is not drained to much. if you leave lights on untill its flat then a jump starter won't help.
tweak'e (69)
1421992 2016-06-16 01:07:00 You could work it out, find out the wattage of the 4 bulbs, add them together, divide by 12 and you'll have the current draw.
Then if your battery list an AH capacity you'll have a rough idea.

For example if it was 40W (total guess) that's 3.3 amps x 4 hours you left them on for is 13-14 AH of battery capacity used. A small car battery starts around 40-50 AH so it's maybe a 3rd of the total capacity.

However car batteries are not designed for constant loads or deep discharges so they don't perform as well as say a deep cycle battery under the same conditions and it's probably worse than what my guesstimate indicates. What I don't know is how much charge is required to start a car. Don't leave your park lights on for extended periods.
dugimodo (138)
1421993 2016-06-16 01:34:00 I'd say it done fairly well to last 4 hours+ actualy bevy121 (117)
1421994 2016-06-16 03:28:00 I may just replace the batt anyway, nothing worse than being stranded somewhere with a dead batt .
I'll check the crank voltage with old & new batt , just out of interest

has anyone got one of those small emergency car starters (jumpstarters), small lipo pack designed to start the car when batt is dead?
that would be a great bit of kit, if the price was right. $200 is a bit much for my pockets , anyone know of where I can get them cheaper?
like this , but cheaper
www.supercheapauto.co.nz

cheers Dont know about the mini ones like that, guess you are paying for the convenience of being compact as well. If you scroll down to the bottom of the linked page the local garage loaned me one of theirs when my battery in the old car decided to play up last year, it was similar to the one advertised at $77.40.
wainuitech (129)
1421995 2016-06-16 04:34:00 How long should a car be able to leave the parking lights on without the batt going flat ?

I accidently left my parking lights on for what seemed like 4 hours, (may have been longer ?), after that the batt was flat .

Is my car batt at its end of usefull life? .No issues with cold cranking etc & it charged up within 10 minutes of driving .
Im guessing the batt is 3-5 years old , Id have to dig out the receipt to be sure

Well call me “Old Fashioned” but I would expect my park lights to be able to be left on through the hours of darkness and the car still start the next day. ;)

However, the total life of the battery is a different matter, and I’m at a complete loss to explain how the battery manufactures have designed their batteries to die one day out of warranty. :rolleyes:
B.M. (505)
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